Hand operated crimping tool



Dec. 9, 1958 Filed Jan. 17, 1957 R. F. COBAUGH ET AL HAND OPERATED CRIMPING TOOL 4 Sheets-Sheet l INVENTOR.

Robert F? auqh Nerf/n L. K/my/er 1958 R. F. COBAUGH ETAL 2,863,346

HAND OPERATED CRIMPING TOOL 4 Sheets-Sheet 2 Filed Jan. 17, 1957 WW a M w f 5 mm x m. 1 .L. w/%\ f H W 1m, My W Dec. 9, 1958 R. F. COBAUGH ET AL 2,863,346

HAND OPERATED CRIMPING TOOL 4 Sheets-Sheet 5 Filed Jan. 17, 1957 I a R. U/ 0 .0 0/ m @m r. mE m u a R Y M B 4 Sheets-Sheet 4 R. F. COBAUGH ET AL HAND OPERATED CRIMPING TOOL R R m mm N B N WOU FL. m E B R 0 RUM Y B Dec. 9, 1958 Filed Jan. 17, 1957 United States Patent HAND OPERATED CRllVIPING TOOL Robert F. Cobaugh, Harrisburg, and Martin L. Klingler,

Hershey, Pa., assignors to AMP Incorporated, Harrisburg, Pa.

Application January 17, 1957, Serial No. 634,756

Claims. (Cl. 81-15) In the art of crimping electrical connectors to a conductor, a high degree of thrust is required. When a hand tool is employed to effect this crimp, the tool must be designed to provide this thrust while remaining within the abilities of an ordinary human to operate the tool.

Special connector applications require special tool design. Some types of connectors require multi-cycle crimping operations when different degrees of thrust are required to crimp diiferent sections of the connector.

It is an object of the present invention to provide a hand crimping tool capable of crimping an electrical connector to a conductor by application of different crimping pressures to various sections of the connector during progressive stages of the crimping cycle, e. g., the connector set forth in the patent application filed March 26, 1956, Serial No. 573,709, by Robert F. Cobaugh.

It is also an object of this invention to provide such a tool with an actuating means capable of easily achieving a high thrust and capable of functioning in limited operating space.

It is a further object of this invention to provide a new valving structure to cause the tool to operate in multistage cycles as set forth above.

it is also an object of this invention to provide a die means having relatively operable die sets for effecting muiti-cycle crimping operations.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

in the drawings:

Figure 1 is a partially cut away, exploded, perspective view of a tool embodying principles of the invention;

Figure 2 is a perspective View of the movable dies and positions;

Figure 3 is a perspective view of the actuating means;

Figures 4 to 6 are plan, sectional views of the tool shown in Figure 1, during successive stages of operation;

Figure 7 is a sectional view taken along plane VIIVH of Figure 3;

Figure 8 is a perspective view of a connector adapted to be crimped to a conductor in two steps;

Figures 9 and 10 are perspective views of the connector of Figure 8 in relation to the tool head shown in Figures 1 and 2.

Figure 11 is a perspective view similar to Figure 1, showing the manner in which the head of the tool is assembled,

Figures 12 and 13 are enlarged views of the valve members 58 and (Figures 4-6).

As shown in Figures 1 and 5, the tool consists of three main portions, a head H, a body B, and actuating means A.

The head H, as shown in Figure 1, consists of a C- shaped member 10 with a die receiving section 12 centrally supported therein. A stationary die member 13 (see Figure 10) is fitted therein. One end of the head H is threaded at 14 whereby it is joined toone end of the body B.

The body B is also cylindrical and consists of a portion 16 of a diameter equal to the diameter of the head and a reduced diameter portion 18.

The main body portion 16 forms a chamber for a movable piston 20 (Figure 1). A die actuating member 22 is axially secured to the piston 20 and it has an actuating surface 24 thereon. A second piston 26 is coaxial with the first piston 20 and also has an actuating member 28 with an actuating surface 36 thereon positioned to cooperate with the first actuating surface 24. The first and second pistons are movable together as well as relative to each other. The first actuating surface 24 is recessed and the second actuating surface fits into it so that they cooperate to form a single actuating means in this nested position. However, relative movement of the pistons causes the second actuating member to ,move independently and operate separately from the first.

These pistons are assembled with their actuating member in nested position and fitted into the main body 16. As shown in Figure l, the pistons bottom on the shoulder 32 formed by the reduced diameter portion 18. A spring 34 urges the pistons against the shoulder in what will be termed the initial position.

A body of fiuid 36 is contained in the reduced chamber 18 so as to bear upon the piston 20. A reduced diameter piston 38 is positioned in the portion 18 to form a chamber for containing this fluid.

A threaded screw 40 is movable longitudinally in the chamber 18 to move the piston 38. A ball bearing 42 is positioned between the threaded screw 46 and the piston 38 to reduce friction. A rotary handle 43 constitutes the means for causing longitudinal travel of the piston 33. The threaded screw 40 cooperates with a bearing box 46 which is fixed to the reduced diameter portion 18.

As shown in Figure 7, the inside of the bearing box 46 contains complementary screw threads 48 which cooperate with the screw threads on member 40 to form a ball bearing raceway. This raceway contains ball bearings 56 which reduce the friction'between the threaded member 40 and the bearing box 46. Opposite ends of the raceway 48 in the bearing box 46 are connected by a channel 52, so that the ball bearings travel in a continuous path while the threaded member 40 is being rotated. When the ball bearings reach the end of the path of travel, they are recirculated through channel 52 so that they travel continuously with the threaded member 40. The portion 54 of the raceway protruding from the bearing box 46 comprises in the present form a member separate from the bearing box for ease of manufacture but may be integral therewith. This particular bearing connection provides a very low moment of friction so that the crank handle 42 is of a minimum operational radius. Such construction permits the tool to be used in very narrow spaces.

Returning to Figures 4 to 6, the pistons 26 and 26 are so nested that a thrust on the under side 56 of piston 20 causes both of them to move upwardly. in the initial stage of deforming a connector, the resistance to crimp- 0 ing is relatively light, since the connector is merely wrapped around the conductor. Continued movement aseasae of the piston 20 deforms the connector onto the conductor. The resistance to crimping is thus increased until further travel of the piston 2G is prevented. When the piston 24 has reached the upper limit of its travel, increased thrust releases a spring loaded valve 53, permitting fluid flow through a channel as, which is longitudinally disposed in the piston 243. Fluid pressure acts directly on the under side 62; of the piston 26. This thrust causes piston 26 to move upwardly relative to the piston 2d which has become stationary. The upward movement of piston 26 operates the second actuating member 28 to perform the second stage of the crimping operation.

As shown in the drawings, the spring loaded valve is comprised of a valve body '79 which inclosed position bears upon valve seat 72 to prevent fluid flow therethrough. One end of spring member 74 bears upon the valve body 74) and the other end bears against a recess '76 in the under side 62 of piston 26. As the piston 26 moves upward relative to piston 2%, the distance between the recess 7d and the valve seat '72 is increased so that the pressure of spring 74 forcing the valve body 70 against the valve seat 72 is decreased. Once the piston 26 begins its upward travel, the thrust tending to hold the valve body 60 closed is decreased. This provides a safeguard against malfunction of the valve 58.

A second pressure operated valve 89 is provided in the piston 2d. Valve St} operates to prevent fluid flow from chamber 36 to the underside 62 of piston 26 but permits fluid flow in the opposite direction. The spring 82 urges a ball 84 against valve seat as and is held in place by a threaded sleeve 88. When fluid pressure in the chamber 36 is equal to the pressure on piston 2f", then the valve is in balance and the spring $2 maintains it in a closed position. However when the fluid pressure is relieved in chamber 36, downward movement of piston 2t overcomes spring 32 to permit fluid flow through the valve 89, thus evacuating the fluid.

A particular embodiment of connector useful with the tool set forth in this application is shown in Figure 8. The connector is described and claimed in the aboveidentified application and consists of ferrule forming members 6, 6, with tabs '7, 7 extending into slots 8, d. The ferrule forming members 6, 6 are deformed onto a conductor with a high degree of pressure to effect crimped connection with good electrical and mechanical properties. In the same operation tabs '7, '7 are forced into cooperating slots 8, 8 (Figure 9). The second stage of the crimping operation occurs when the tabs are deformed to lock them into the slots permanently, as shown in Figure 10.

The crimping members employed include a stationary die member 13 and a relatively movable die member 15 (see Figures9 and 10). The stationary die member 13 includes an arcuate working surface 17 which receives the ferrule forming portions 6 6' of the connector and deforms it into the conductor during the crimping operation.

The relatively movable die member 15 also includes an arcuate working surface l; which cooperates with the working surface 17 on the stationary die member 13. A locate-r means in the form of a pin 21 locates the connector, as set forth more fully in the above-identified application.

A slot 23' is located adjacent the working surface i This slot is disposed parallel to the line of travel of the relatively movable die member 15. The lower surface 25 of the base 27 of the relatively movable die member 15 contains a recess 31. The slot 23' extends from the surface adjacent the working surface 19 to the recess 31.

A deforming pin 23 (which may be considered to be a second movable die) is slidably disposed in the slot 23'. A projection 29 on the pin 23 travels in a slot and functions to limit the longitudinal travel of the pin. For ease of assembly the projection 29 is shown extending through the exterior surface of the tool and threadedly secured to the pin 23. As shown in Figures 9 and 10 the pin 23 moves between a first or inoperative position wherein one end extends into slot 31 and the other end is recessed from or flush with the surface of the die member 15 (Figure 9) and a second or operative position wherein the lower end of the pin 23 is flush with the innermost surface of the recess 31 and the other end of the pin projects beyond the die member 15 (Figure 10).

The crimping operation is effected by inserting the connector into the open die members with the conductor disposed therein. Rotation of the handle 42 causes the pistons 20, 26 to travel as a unit, carrying the relatively movable die member 15 therewith. The pistons are in the position shown in Figure 5 and the pin 23 is inoperative as shown in Figure 9. When sufficient pressure is developed to crimp the connector onto the conductor, a further generation of pressure actuates valve 61 admitting fluid to the working surface 62 of piston 26.

Continued thrust causes the piston 26 and consequently actuating surface 36 to continue its upward movement while the piston 2i) remains stationary.

As shown in the drawings, the die member 15 is actuated by the piston Ztl. While the pistons 26 ant 26 are moving in unison, the actuating member 2% secured to piston 26 is inoperative by reason of the actuating surface 3d being flush with the upper surface 24 of the die actuating member 22 of the piston Zil. Vvhen the piston 26 moves relative to piston MP, the actuating surface 3i enters recess 31 of the die member 15. Continued relative upward movement of the piston 26 causes the actuating surface St to raise the pin Thus the crimping pressure is transmitted through the pin 7.3 to deform the connector tabs into a locked position.

We claim:

1. A device for crimping electrical connectors onto conductors in two stages including a first fluid operated crimping die member, a second fluid operated crimping die member, and a single fluid system for operating both die members including means for operating both die members simultaneously until the first die member reaches the limit of its travel and then permits the second die member to continue its travel, until the connector is crimped to the conductor.

2. The device of claim 1 wherein the second die memher is disposed centrally of the first die member and the first and second die members have separate coaxial pistons, and the means for permitting separate travel of the second die member comprises a valve means in the first piston.

3. The device of claim 2 including a spring for returning the pistons to their initial position.

4. In a fluid operated hand tool for crimping electrical connectors onto conductors, the improvement comprising a first piston with a die actuating member centrally positioned thereon, a second piston coaxial with the first piston surrounding the die actuating member, a second die actuating member located on the second piston, a die member secured to the die actuating members, a central recess in said die, said second die actuating member being so arranged as to be positioned in the central recess of the die member.

5. The device of claim 4 including a valve means in the first piston designed to release at a predetermined pressure to permit fluid flow through the first piston to operate the second piston, and return valve means normally closed, operable to permit fluid to flow in the reverse direction.

6. A hand tool for crimping electrical connectors to conductors including a head having a fixed die therein, a body secured to the head, a movable die assembly in the body which cooperates with the fixed die to perform the crimping operation, the movable die assembly being comprised of a primary movable die secured to a primary piston by an axial stem, a fluid chamber in the body with the primary piston axially disposed therein, a body of fluid in the chamber adjacent the surface of the piston, a secondary piston surrounding the stem of the primary piston and movable with the primary piston as well as being slidable on the stem, whereby it may be displaced from the primary piston to form a second fluid chamber therewith, a spring loaded valve in said primary piston which permits flow of fluid through the primary piston when the valve is subjected to a predetermined fluid pressure, a second movable die disposed centrally of the first movable die and secured to the secondary piston, and means to operate the pistons.

7. The device of claim 6 wherein one end of the chamber has a reduced cross sectional area, and a third piston in the reduced area portion of the chamber, whereby a low pressure exerted on the third piston over a relatively long path of travel results in a high pressure exerted on the primary and secondary pistons over a relatively short path of travel, and means for operating the third piston including a threaded connection with a recirculating ball bearing raceway.

8. A die member for deforming an electrical connector including a die body, a work face on one side of the body, a deforming pin slidably mounted in the die body for relative movement therewith between a first position wherein the working end of the deforming pin is inoperative with respect to the working face and a second position wherein the working end of the deforming pin projects from the working face, and means for moving said pin relative to the die body.

9. The device of claim 8 wherein the end of the deforming pin opposite from the working end projects from the side of the die body opposite from the working face.

10. The device of claim 9 wherein the opposite side of the die body is slotted and the opposite end of the pin projects into the slot in the first position.

References Cited in the file of this patent UNITED STATES PATENTS 2,254,613 Matthysse Sept. 2, 1941 2,693,218 Freedom Nov. 2, 1954 2,696,850 Peterson Dec. 14, 1954 2,762,414 Demler Sept. 14, 1956 2,729,063 Hoadley Jan. 3, 1956 

